Control system for operating a plurality of sewing machines



K. WINZ May 8, 1962 CONTROL SYSTEM FOR OPERATING A PLURALITY OF SEWING MACHINES Filed Oct. 9, 1958 INVENTOR. K!) 84. N/NZ United States Patent Ofiice 3,033,142 Patented May 8, 1362 3,033,142 CONTROL SYSTEM FOR OPERATING A PLU- TRALITY F SEWING MACHINES Karl Winz, Kaiserslautern, Pfalz, Germany, assignor to G. M. Pfatf A.G., Kaisersiautern, Pfaiz, Germany Filed Oct. 9, 1958, Ser. No. 766,299 Claims priority, application Germany Oct. 14, 1957 3 Claims. (Cl. 112-219) The present invention relates, in general, to automatic sewing machines and, in particular, to an apparatus for controlling the initiation of the operating sequence of a plurality of sewing machines.

In sewing machine plants, a single operator may frequently have to control the operation of a plurality of automatic sewing machines. He must take care of feeding the material to be sewn to the machines, the insertion of the material into each of the machines, and the subse quentstart of operation of each machine.

If, in addition to the foregoing, he must start the operation of the machines in a predetermined order or after a constant or varying time interval, it is apparent that he cannot perform all of these duties.

It is an object of the present invention to provide means permitting the automatic control of a plurality of sewing machines so that the operator need not be concerned with the correct starting sequence thereof and, consequently, he can concentrate only on the feed of the sewing material and the insertion thereof into the machines.

It is another object of the present invention to provide means permitting the freeing of the operator to perform the aforesaid duties and which, nevertheless, permits for variation in the starting time intervals of the various sewing machines.

It is another object of the present invention to provide means rendering it possible to permit for the provision of a time switch which can be influenced by a circuit closing relay of one automatic sewing machine which has its contacts disposed in the energizing circuit of a second automatic sewing machine.

It is another object of the present invention to provide means permitting the operator to prevent the automatic start of a sewing machine in the event of unforeseen delays in the insertion of the sewing material.

It is another object of the present invention to provide means ensuring that each automatic sewing machine is started only after its cloth presser foot has been lowered to the operative position thereof.

It is a further object of the present invention to provide for a highly eflicient and generally simplified system for the control of a plurality of automatic sewing machines.

These and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawing showing a preferred embodiment of the invention.

The sole figure of the drawing, which represents the best mode presently contemplated of carrying out the in vention, is a schematic wiring diagram of an automatic sewing machine control system according to the present invention.

Pursuant to the present invention, a plurality of different switching operations is performed automatically through the provision of a time controlled switch which is subjected to the control of an electromagnetic relay utilized to close the circuit of one of the automatic sewing machines, said relay having contacts arranged in the energizing circuit of a second automatic sewing machine. It is not necessary that these contacts be located in the energizing circuit of the adjacent machine, they can, in

addition, effect the initiation of oepration of any of the following automatic sewing machines. For this purpose, there is provided also an impulse switch which is connected with the circuit closing electromagnet or relay of each machine in such manner that an operating contact of the impulse switch is located,after the energization of the circuit closing relay, in the energizing circuit of the time switch, a holding circuit being closed through another contact thereof after operation of the time switch.

The control of the initiation of operation of an automatic machine is effected by a reversing contact which operates after the variable time delay of the time controlled switch has elapsed.

Said reversing contact is located on the side of the res contact in the energizing circuit of the relay for lifting the cloth presser foot, and on the side of the working contact in the energizing circuit of the circuit-closing relay. In order to enable the operator to prevent the automatic initiation of operation of a sewing machine in case, for example, of unforeseen delays in the insertion of .the sewing material in the machine, provision is made for an emergency switch which can be operated by the operator whenever necessary. This switch is in the energizing circuit of the relay which lifts the cloth presser foot and is independent of the reversing contact of the time control switch. In order to provide for the automatic disconnection of the time sviu'tch, a circuit breaker, whose contact is in the holding circuit of the holding circuit of the time switch of its own machine, is in positive connection with the circuit closing relay in such a way that the holding circuit of the time switch is opened after the energization of the circuit closing relay. In order to insure that each automatic sewing machine is started only after its cloth presser foot has been lowered into operative disposition, provision is made for a safety switch which is so connected with the relay for lifting the cloth presser foot of each sewing machine that a rest contact for this safety switch is located'in the energizing circuit of the circuit closingv relay after the relay has been deenergized.

Referring now to the drawing in detail, there is shown the wiring diagram of series of three automatic sewing machines, it being understood that the present invention is not limited to three machines and that the number thereof may be increased, as desired. In the present instance, the three machines are designated by the reference characters A, B and C, respectively. Each machine is provided with a presser foot lifting relay or electromagnet, as shown at 1, 51 and 101, respectively; an energizing circuit closing relay or electromagnet, as shown at 3, 53 and 103, respectively; a foot-operated switch for controlling the associated lifting and closing relays, as shown at 3, 53 and 103, respectively; and a safety switch 4, S4 and 104, respectively. In order to prevent the cloth presser foot of each machine from being lifted after the operation of the machine has been initiated, each machine is provided with a cam which is positively driven thereby during operation thereof, said cams being indicated by the reference numerals 5, 55 and for the machines A, B and C, respectively.

Each of the presser foot raising relays 1, 51 and 101 controls an associated safety switch 6, S6 and 106, respectively. i

Each safety switch remains open as long as its associated presser foot raising relay is energized, in order to prevent the associated machine from starting before its cloth presser foot has been lowered into operative disposition.

All the presser foot raising relays and all the energizing circuit closing relays are energized from a suitable D.C. supply which is connected across the terminals 20-21. A DC. power line 7 is connected to the positive terminal 20 and a DC. power line '8 is connected to the negative terminal 21. With the lines 7 and 8 supplied from the DC. source, the conventional cloth presser foot or bar (not illustrated) of the sewing machine A is raised in its inoperative position, since the presser foot raising relay 1 is enregized by the circuit generally indicated by the reference charcter I. Said circuit ex tends from the line 7 through terminal 9, through the lifting relay 1, through the closed safety switch 4, through the engaged contacts 10 of the foot switch 3 to terminal 11 and from the latter to terminal 12 on power line 3. It will be understood that the safety switch 6 is operated by the relay 1, said safety switch being open, as shown, when the relay is energized.

When the operator actuates the foot switch 3 to open the contacts 10 and to close the contacts 13, circuit I is interrupted. This deenergizes the relay 1 so as to close the safety switch 6. The circuit closing relay 2 is now connected to power line 7, at terminal 14, through closed safety switch 6 and to power line 8, at terminal 12, through the foot switch closed at contacts 13. This circuit is designated by reference character Ii. The automatic sewing machine A is now energized in conventional manner and begins to operate. Therefore, it will be apparent that the depression of the foot switch 3 resulted in the lowering of the presser foot and the initiation of the operation of the machine. With the machine in operation, the cam is operated and opens the safety switch 4. When the operator releases the foot switch 3, the contacts are again engaged, but the circuit I being interrupted at safety switch 4 remains deenergized. An impulse switch 15 is operated by the circuit closing relay 2. When relay 2 is energized, switch 15 is actuated to engage the contacts 16.

With power in the lines 7 and 8, the presser foot lifting relay 51 of the sewing machine B is energized through the circuit III which extends from terminal 57 on line 7, through relay 51 and the closed safety switch 54 to terminal 58, from the latter through the closed contacts 59 of foot switch 53 to terminal 60, through reversing contact 61 of a time switch 62, to terminal 63 and from the latter to terminal 64 on power line 8.

The presser foot raising or lifting relay 101 is energized through an identical circuit IIIA which extends from terminal 57A of power line 7 through relay 101, closed safety switch 104, terminal 58A, closed contacts 59A of foot switch 103 to terminal 60A engaged by the reversing contact 109 of time switch 107, to terminal 63A and from the latter to terminal 64A at power line 8. With the relays 51 and 101 energized, the presser bars (not illustrated) of the machines B and C are raised and said machines are inoperative.

Upon engagement of the contacts 16 by the impulse switch 15, as previously described, the time control switch 62 is connected across the A.C. power lines 65 through the circuit identified by the reference charcater IV, as follows: from terminal 66 on one of the -A.C. lines 65, through the closed circuit opening switch 67, through the time control switch 62, through the engaged contacts 16 of the impulse switch 15 to terminal 68 and from the latter to terminal 69 of the other A.C. power line 65. The time switch being energized closes its working contact 70 and remains energized in a holding circuit, identified by the reference numeral V, as follows: from terminal 66 of the upper A.C. main 65, through the circuit interrupting switch 67, through the time controlled switch 62, through the closed operating contact 70 to terminal 68 and from the latter to terminal 69 of the lower A.C. main 65.

Until the elapse of the time interval or period for which the time switch 62, which is of conventional construction, is set to respond, the machine B remains inoperative with its presser bar raised so that the operator can insert the material into the sewing machine B. After the preset time has expired, the switch 62 operates in well known manner and its reversing contact 61 is operated to disengage the contact 60 and engage the contact 73. The disengagement of contacts 60*61 interrupts the encrgizing circuit of the presser bar raising relay 51. The relay is deenergized so that the associated presser bar is lowered and the associated safety switch 56, controlled by relay 51, is closed. With the reversing contact 61 engaged with the contact 73 there is completed a circuit which is indicated by the reference character VI for energizing the circuit closing or starting relay 52 for the sewing machine B as follows: from terminal 71 of DC. power line 7 through the closed safety switch, through the relay or electromagnet 52, through one contact 72 of the foot switch 53, through the engaged contacts 73-61, to the terminal 63 and from the latter to the terminal 64 on DC. power line 8.

The relay 52 being energized, the sewing machine B begins ot operate in conventional manner and the circuit interrupting switch 67, which is controlled by relay 52, is opened so that the holding circuit V of the time switch 62 is interrupted and the latter is automatically reset in known manner. An impulse switch 74 is also operated by the relay 52 in the same manner as the operation of the previously described impulse switch 15 by relay 2. Consequently, upon energization of relay 52, switch 74 closes contacts 75 to energize a time switch 107 of sewing machine C to set said time switch running. Time switch 107 is connected across the A.C. mains through a circuit IVA which is similar to circuit IV. Circuit IVA extends from terminal 66A at the upper A.C. main through the closed circuit interrupting switch 110, through the time switch 107, and through the engaged contacts 75 of switch 74 to terminal 69A on the lower A.C. main 65. With the time switch 107 energized, its working contact 108 is closed to provide a holding circuit VA therefor which extends from terminal 66A through closed switch 108, through the time switch 107 and its closed contact 108 to terminal 69A on the lower A.C. main.

After the lapse of the present time period, the switch 107 operates its reversing contact 109 to disengage the contact 60A and engage the contact 73A so as to energize the circuit closing relay 102 of the machine C through the circuit indicated by the reference character VIA. Said circuit may be traced as follows: from terminal 71A at DC. power line 7 through the safety switch 106 which is closed upon deenergization of the relay 101 due to disengagement of contacts 60A and 109, through the relay 102 through one contact 72A, through the engaged contacts 73A-109, to terminal 63A, and from the latter to terminal 64A of power line 8. The operation continues, as previously described in connection with machine B, the circuit closing relay 102 operating to open the switch 110 so as to interrupt the holding circuit VA for the time switch 107 and said relay also operating, when energized, to close the impulse switch 111 at the contacts 112 whereby to connect the time switch of another sewing machine (not illustrated).

If, during the insertion of the work into the sewing machine B, for example, the operator notices that the time remaining before operation of the time switch 62 to close and to start the machine is insufficient he can actuate an emergency switch which provides a holding circuit for the presser foot, which circuit is independent of the reversing contact 61 of the time switch 62.

Said emergency holding circuit is indicated by the reference character VII and may be traced as follows: from terminal 57 of DC. line 7 through lifting relay 51, through safety switch 54 to terminal 58, through the closed emergency switch 76 to terminal 63 and from the latter to terminal 64 of power line 8. As long as the emergency switch 76 is held closed, the automatic switching operations of the time switch 62 remain ineffective. Upon release of the closed emergency switch 76 to open the latter, the machine B is connected over the reversing contact 61, as previously described. A corresponding emergency switch 113 and corresponding circuit VIIA are provided in the sewing machine C and operate inthe same manner.

It will be noted that in each machine the corresponding safety switch 4, 54 and 104, respectively, is opened by the corresponding machine operated cam 5, 55 and 105, respectively, upon operation of the associated machine so that the associated lifting relay 1, 51 and 101, respectively, is deenergized to prevent the presser foot of the associated machine from being lifted after the machine has started.

Various changes and modifications may be made without departing from. the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A system for controlling a plurality of automatic sewing machines each having a presser foot; comprising a relay for each machine operable to control the raising of the respective presser foot thereof, a circuit closing relay for each machine for controlling the operation thereof, a time control switch for at least one machine responsive to the operation of the circuit closing relay of another machine, said last mentioned relay controlling the closing of open contact means in the energizing circuit of said time control switch, each machine having a safety switch in the energizing circuit of the circuit closing relay thereof, said safety switch being operable under the control of the raising relay of the associated machine, and said safety switch being open during energization of the associated raising relay and being closed in response to deenergization of the associated raising relay, whereby the associated machine cannot be operated until its pressure foot has been lowered.

2. Control apparatus for a plurality of automatic sewing machines each having a presser foot; comprising a relay for each machine operable to control the raising of the respective presser foot thereof, a circuit closing relay for each machine for starting the operation thereof,

and a time control switch for at least one machine responsive to starting of the operation of the circuit closing relay of another machine, said last mentioned relay controlling the closing of open contact means in the energizing circuit of said time control switch, each machine having a cam operated switch in the energizing circuit of the associated raising relay for deenergizing said relay in response to operation of the associated machine.

3. A control device for operating a plurality of sewing machines each including means such as a depressable presser foot connected to means for energizing the sewing machine drive to operate the machine, comprising an electrically energized circuit, relay means in said circuit for raising said presser foot when energized, means connectable to said sewing machine drive for de-energizing said circuit and said relay means when said sewing machine is operating, a second circuit for operating the next machine including time delay means therein and relay means for raising said presser foot of said next machine when energized, and means connected to said presser foot of said first machine and movable upon depressing of said presser foot to energize said second circuit, said second circuit being opened by said time delay means until the expiration of a preselected time, the presser foot of the second machine thereafter being effective to initiate operation of said next machine upon the manual lowering thereof. 

